adj
Containing sufficient poison to be dangerous to touch or ingest.
While highly poisonous to dogs, this substance is completely harmless if ingested by humans.
Nor taint-worm ſhall infect the yeaning herds / Nor penny-graſs, nor ſpearwort's poiſ'nous leaf.
Of an animal such as a snake or spider, or parts of its body: producing a toxin intended for defensive or offensive use which is usually injected into an enemy or prey by biting or stinging; hence, of a bite or sting: injecting poison.
Poisonous snakes should only be handled by experienced professionals.
SERPENT … either that which is not poiſonous: or that which is counted poiſonous, having two long, hollow, moveable teeth, …
Negative, harmful.
He didn't want to end up like his grandfather, bitter and intractable, consumed in his hatred like an addict on haze — a poisonous attitude that would possess him all his remaining years.